I've recently started learning how to use Blender and I have a few questions:
1. Is it possible to create a new verticle on an existing edge (that's what a line between to verticals is called right?).
I know I can add single verticles but it would be easier if I could just select a part of an edge and add it to the spot.
2. I've set language to Dutch, but still everything is in English, is there a Dutch translation?
3. This might be a bug but maybe I've just pressed the wrong button, sometimes blender stops reacting to my keyboard.

I am doing the tutorials on blender3d.org, in case you want to point me there, I'm already busy with that.

press TAB
select the points of the edge
press W
select "subdivide" from the menu

voilà

another couple of hints:
-you can subdivide any arbitrary ammount of edges at the same time (by selecting the edgese's vertices)
-if you select all the vertices of a plane you can subdivide that plane
-if can limit the subdivisions on a plane by selecting the "beauty" button in the edit buttons ( F9 KEY) it will be subdivided only on the longest edges

I hope this can help you, but for the future questions like these are better posted on www.elysiun.com forums.
They are devoted to the use and learning of Blender so you can get better answers.
The blender.org forums are for the development and bugtracking of Blender so for the question number 3 that's the right place

also, if you don't want the sibdivided vert to be in the middle of the edge, you can slide it using a scaling function.

TAB into editmode and select the vertex you want it to be closer to.
eg, A..........B..........C
select A
SHIFT+S (snap menu), cursor to selection.
press dotkey [.], to activate rotate/scale around cursor.
now select B, hit S to scale.
B will slide along the edge towards A, keping the straightness of the edge intact.